Goblin Welder is on the shortlist of all-time strongest one-drops, and its ability to turn a random mana rock or an artifact land into Blightsteel Colossus (or vice versa on an opponents side!) is simply unmatched
Comet Storm X spells that deal damage like Comet Storm can be used as finishers in the right deck
It has a decent power and toughness, making it not completely irrelevant in the field of battle, so it may see some play
In practice, shuffling once is sufficient, but effects that care about you shuffling your library (like Psychogenic Probe, for example) will see that you've shuffled twice
That's actually a rather good depiction of someone in a bout of vertigo
When the Disappear keyword triggers at the start of your end step, you can cast a card exiled by the duo for free